Degradable materials have been used in various subterranean applications because of their ability to degrade and leave voids, temporarily restrict the flow of a fluid, and/or produce desirable degradation products. Poly(lactic acid) (“PLA”) has been used a degradable material because it degrades in subterranean environments after performance of a desired function or because its degradation products may perform a desired function, such as, for example, degrading an acid soluble component or controlling fluid losses. Control of fluid losses, or lost circulation, allows drilling to continue while keeping the wellbore full, preventing an influx of gas or fluid into the wellbore, which can lead to a blowout. Lost circulation occurs when a bit used for drilling operation encounters natural fissures, fractures or caverns, and mud flows into the newly available space. Lost circulation may also be caused by applying more mud pressure (that is, drilling overbalanced) on the formation than it is strong enough to withstand, thereby opening up a fracture into which mud flows.
Controlling the degradation of the degradable material, particularly to achieve control of fluid losses, is important. For instance, a diverting agent formed from a solid particulate degradable material would be of little or no use if it degraded too quickly when placed in a portion of a subterranean formation from which diversion was desired. There exists a need for relatively low-cost controlled degradation fibers for which is it possible to control degradation in various applications.